With fast development of mobile communications technologies, mobile communications systems of a plurality of standards emerge, such as a GSM (Global System for Mobile Communications) network, a GPRS (general packet radio service) network, a WCDMA (Wideband Code Division Multiple Access) network, a CDMA-2000 network, a TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) network, and a WiMAX (Worldwide Interoperability for Microwave Access) network. In addition to providing a voice communication service, these mobile communications systems generally further provide a data communication service. Therefore, a UE may use the data communication service provided by these mobile communications systems to upload and download various types of data.
In the prior art, CoMP (coordinated multipoint) is used to improve reliability of a terminal at an edge of a cell and CA (carrier aggregation) is used to increase throughput of a UE. However, if an environment of the terminal deteriorates, the throughput and/or reliability of data transmission of the terminal rapidly decline.
At present, a concept of MUCC (multiple UE cooperative communication) is put forward. In a multiple UE cooperative communication technology, a D2D (device to device) communication technology implements communication between terminals, thereby making it possible to have same support between the terminals. Therefore, data that a base station sends to a terminal can be sent to another terminal (namely, a supporting terminal, which is expressed as an S-UE) adjacent to the terminal and then forwarded to a final destination terminal (namely, a beneficed terminal, which is expressed as a B-UE) by using a near field communication technology between the terminals. In this way, a terminal with a good channel condition can be selected as an S-UE from a plurality of terminals, which increases an edge rate of a UE by using a multiple UE diversity gain, thereby improving spectrum utilization.
In the D2D technology, a proximity discovery technology and the near field communication technology are a basis of multiple UE cooperative communication. In the proximity discovery technology, after a device that needs to enable a proximity discovery function initiates a request for enabling the proximity discovery function to a near field service server, the near field service server allocates broadcast information dedicated to proximity discovery to the device that initiates the request. The broadcast information is a near field identifier or a D2D code (D2D Code), which is a unique identifier of a device for implementing global proximity discovery. On one hand, the device that acquires the D2D code announces its existence in a current position by using a predefined rule to externally broadcast a signal carrying the D2D Code, so as to help other devices to discover the device that acquires the D2D Code. On the other hand, the device that acquires the D2D Code uses the predefined rule to monitor a signal that is broadcast by the other devices and carries the D2D Code. When the device receives the signal that is broadcast by the other devices and carries the D2D Code or after the device receives the signal that is broadcast by the other devices and carries the D2D Code and successfully attempts physical layer interaction with the other devices, it indicates that the other devices are within a near field range.
The prior multiple UE cooperative communication technology provides neither a cooperative communication trigger mechanism nor a scheme for accurately finding a cooperative communication UE of a terminal.